Sodium Bromide → 4-(Pyridin-4-yl)benzoic acid

HRID 1937046Notes

Reaction equation

HRID 1937046 reaction equation
[C:1]1(C)[CH:6]=[CH:5][C:4]([CH:7]2[CH:12]=[CH:11][N:10](C(=O)C(C)(C)C)[CH2:9][CH2:8]2)=[CH:3][CH:2]=1.[Br-].[Na+].[C:22](=[O:25])(O)[O-:23].[Na+]>O.O.O.O.C([O-])(=O)C.[Co+2].C([O-])(=O)C.O.O.O.O.C([O-])(=O)C.[Mn+2].C([O-])(=O)C.C(O)(=O)C>[C:22]([C:1]1[CH:2]=[CH:3][C:4]([C:7]2[CH:8]=[CH:9][N:10]=[CH:11][CH:12]=2)=[CH:5][CH:6]=1)([OH:23])=[O:25]

Participants

7

Reactant 3

HCID 253881Sodium BromideHCID 516892Sodium BicarbonateHCID 70162423HCID 70162423, compound

Product 1

HCID 15208114-(Pyridin-4-yl)benzoic acidYield 90%

Reagents, catalysts & solvents 3

HCID 61372Cobalt(II) acetate tetrahydrateCatalystHCID 93021Manganese acetate tetrahydrateCatalystHCID 176Acetic AcidSolvent

Conditions

Temperature
162.5 °C

Procedure

177.2 g (0.75 mol) of 4-p-tolyl-N-pivaloyldihydropyridine, 1511.2 g of acetic acid, 3.74 g (15.0 mmol) of cobalt(II) acetate tetrahydrate, 3.68 g (15.0 mmol) of manganese(II) acetate tetrahydrate and 3.09 g (30.0 mmol) of sodium bromide are placed in a 3.5 l autoclave. The autoclave is made inert using nitrogen and is heated to 160-165° C. When this temperature has been reached, about 450 l/h of air are introduced and an internal pressure of 16-18 bar is maintained by means of a pressure maintenance device. Air is introduced for about 30-40 minutes, the autoclave is then once again made inert by injection of nitrogen and the mixture is cooled. The greenish solution (becomes orange-red on cooling) is taken from the autoclave and evaporated to a weight of 370 g on a rotary evaporator. The thick suspension is filtered on a suction filter and the crystals are washed 3 times with 50 g each time of 75% strength by weight acetic acid. The crude product obtained in this way is taken up in 75 ml of 0.4% strength by weight sodium bicarbonate solution, stirred for 30 minutes at about 50° C. and filtered off. Drying leaves 4-(4′-carboxyphenyl)pyridine in a yield of 90%. HPLC purity: >98% (a/a).

Workup

  1. additionabout 450 l/h of air are introduced
  2. temperaturean internal pressure of 16-18 bar is maintained by means of a pressure maintenance device
  3. additionAir is introduced for about 30-40 minutes
  4. temperatureonce again made inert by injection of nitrogen and the mixture is cooled
  5. temperatureThe greenish solution (becomes orange-red on cooling)
  6. customevaporated to a weight of 370 g on a rotary evaporator
  7. filtrationThe thick suspension is filtered on a suction
  8. filtrationfilter
  9. washthe crystals are washed 3 times with 50 g each time of 75% strength by weight acetic acid
  10. customThe crude product obtained in this way
  11. filtrationfiltered off
  12. customDrying

Sources & evidence

ORD record
ord-5ebefe4cd031487192dd819e37d110b3
Source dataset
uspto-grants-2002_05
Patent number
US06392051B2

Reaction notes

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